Examples

Single grain sushi is sold in plates of 10 or 12 (arranged in a circle with a couple of strips of leek in the middle to form the hands of a clock) and features all the typical sushi, including makimono, tako, tamago, ikura, kohata, anago, ebi, ika, Otoro and kanpachi.

"Alice Mabel Bacon, who spent much time in Japan, introduced the word "sushi" into the English language in 1893, in her book A Japanese Interior. It is doubtful that this sushi, which she described as "rice sandwiches," was made with fish. We do know that the "sushi" included on the menu of a Japanese dinner in the fall of 1894 at the Club of All Nations in Manhattan was not. Almost 30 years later, in the spring of 1924, "sushi" was served on the lawn of the Vanderlip estate, in Scarborough-on-Hudson, at a fund-raising event for a women's college in Tokyo, but it is almost certain that no raw fish was involved. All these early references to sushi are likely to variations of the simple treats of sweet sushi rice wrapped in seaweed or in little soybean cakes that were so popular among Japanese children. Source & citation.

The only thing you need to remember is that sushi is not a raw fish. Sushi means vinegared rice. June 18th was purported as being National Sushi Day, even though no one had ever heard of it before. It seems to be one of those internet holidays, made up by marketing departments to get people to buy stuff – it's not as if that isn't a distinct possibility. Most people who have written about it so far have all pointed out that they had never heard of National Sushi Day, and that it is probably spurious. At any rate, those who go for it might file into Japanese restaurants and get in on celebrating the suspicious National Sushi Day.